Imaging studies offer the potential for non-invasive detection of key molecules that are important in prostate cancer biology and medicine. The goal of the Small Animal Imaging Core is to provide imaging research support to investigators who are involved in defining a prostate cancer signature, often at the molecular level. Imaging studies may serve as a non-invasive phenotypic correlate of the molecular changes. The primary responsibility of the Small Animal Imaging Core will be to provide magnetic resonance imaging capability at the highest spatial resolution possible to monitor the effect of genetic changes and for the study of cancer biology in animal models. We are in the process of upgrading our MR equipment with stronger gradients, and NIH funding has been obtained for a new spectrometer console. A newverticalbore500 MHz system with dedicated microscopy insert is under discussion. Other imaging capability includes a new MicroPet. Optical imaging equipment and a new MicroTare expected to be ordered shortly. As a core facility, the main goal will be to provide state of the art imaging capability. This will take a "two-pronged" approach. We will use medium resolution imaging (1.5 mm slicethickness,~150-300u in plane resolution) for screening mice for development of tumors. We have demonstrated the capability of imaging13 mice simultaneously and were able to detect tumors and hemmorhage in the brain. Animals where in tumor is suspected will be imaged at higher resolution for improved quantitation. Our current goal for the new spectrometer and gradients will be to obtain in vivo spatial resolution of ~ 100u in plane and 0.20-0.50 mm slice thickness for MR. Improvements in image processing and analysis to enhance the accuracy of multi-modality imaging will also be necessary. The Core will provide imaging services to projects1-3 and6. Support for projects1-3 will consist of detection of tumors, measuring their growth rate and response to novel genetic and pharmacologic treatments. Project6 will require MR imaging for providing in vivo an atomic data for correlation with positron emission tomography(PET) and Quantitative Autoradiography (QAR). The lack of anatomical detail provided by PET necessitates the development of good software for correlating PET, MRI, and QAR data. Image correlation using one of several techniques as described will be utilized. Spectroscopic studies will be done to monitor and detect physiologic changes that occur in response to treatment and as a possible early of tumor response.